Pedestal with multi-zone temperature control and multiple purge capabilities

ABSTRACT

Substrate support assemblies for a semiconductor processing apparatus are described. The assemblies may include a pedestal and a stem coupled with the pedestal. The pedestal may be configured to provide multiple regions having independently controlled temperatures. Each region may include a fluid channel to provide a substantially uniform temperature control within the region, by circulating a temperature controlled fluid that is received from and delivered to internal channels in the stem. The fluid channels may include multiple portions configured in a parallel-reverse flow arrangement. The pedestal may also include fluid purge channels that may be configured to provide thermal isolation between the regions of the pedestal.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/723,516, filed Dec. 21, 2012, and titled “PEDESTAL WITH MULTI-ZONETEMPERATURE CONTROL AND MULTIPLE PURGE CAPABILITIES” which claims thebenefit of U.S. Provisional Application No. 61/673,067, filed Jul. 12,2012, and titled “PEDESTAL WITH MULTI-ZONE TEMPERATURE CONTROL ANDMULTIPLE PURGE CAPABILITIES.” The entire contents of both of which arehereby incorporated by reference for all purposes.

TECHNICAL FIELD

The present technology relates to components and apparatuses forsemiconductor manufacturing. More specifically, the present technologyrelates to substrate pedestal assemblies and other semiconductorprocessing equipment.

BACKGROUND

Integrated circuits are made possible by processes which produceintricately patterned material layers on substrate surfaces. Producingpatterned material on a substrate requires controlled methods forforming and removing material. The temperature at which these processesoccur may directly impact the final product. Substrate temperatures areoften controlled and maintained with the assembly supporting thesubstrate during processing. Temperature fluctuations that may occuracross the surface or through the depth of the supporting assembly maycreate temperature zones or regions across a substrate. These regions ofvarying temperature may affect processes performed on or to thesubstrate, which may often reduce the uniformity of deposited films oretched structures along the substrate. Depending on the degree ofvariation along the surface of the substrate, device failure may occurdue to the inconsistencies produced by the applications.

Additionally, the structures housed within a semiconductor processingchamber may be affected by the processes performed within the chamber.For example, materials deposited within the chambers may deposit on theequipment within the chamber as well as on the substrate itself. Thus,for these and other reasons, there is a need for improved equipment andassemblies within semiconductor processing chambers. These and otherneeds are addressed by the present technology.

SUMMARY

Substrate support assemblies for a semiconductor processing apparatusare described. The assemblies may include a pedestal and a stem coupledwith the pedestal. The pedestal may be configured to provide multipleregions having independently controlled temperatures. Each region mayinclude a fluid channel to provide a substantially uniform temperaturecontrol within the region, by circulating a temperature controlled fluidthat is received from and delivered to internal channels in the stem.The fluid channels may include multiple portions configured in aparallel-reverse flow arrangement. The pedestal may also include fluidpurge channels that may be configured to provide thermal isolationbetween the regions of the pedestal.

The first and second fluid channels may be arranged in a coil patternwithin the support assemblies in disclosed embodiments. Additionally,the stem may further include a heating means operable to maintain atemperature of the stem different from the first and second pedestalregions. The first and second fluid channels may be fluidly isolatedfrom one another in order to provide temperature differentiation acrossthe surface. The substrate support surface may additionally be of anynumber of geometries and may be circular. Within this circular design,the first region of the pedestal may be centrally located, and thesecond region may be an annular region surrounding the first region.Subsequent regions may additionally be provided.

In disclosed embodiments the pedestal and stem may be two separatecomponents electrically isolated from one another. Additionally, thefirst and second portions of the first fluid channel may be disposedvertically from one another and may be substantially or directlyvertically aligned. The support assemblies may additionally include afirst purge channel defined within the pedestal and configured toprovide a first purge flow path for a purge gas. The first purge channelmay include a vertical isolation cavity defined between the first regionand second region of the pedestal, and the isolation cavity may beconfigured to receive a portion of the purge gas. The pedestal portionof the assemblies may be formed by coupling one or more plates with eachother, and the pedestal may comprise multiple plates in variousembodiments. A first plate may comprise the substrate support surface,and a second plate may be located below the first plate and have areasdefining at least part of the third and fourth portions of the secondfluid channel, as well as at least a portion of the isolation cavity.

The pedestal may include at least one additional plate located below thefirst plate, or between the first and second plates, that includes areasdefining the first and second portions of the first fluid channel. Theat least one additional plate may further include areas defining atleast part of the third and fourth portions of the second fluid channel,at least part of the isolation cavity, as well as the first purgechannel. The at least one additional plate may be composed of at leasttwo plates, such as a third and fourth plate. The third plate may belocated below the first plate and include areas defining at least partof the first and second portions of the first fluid channel, at leastpart of the third and fourth portions of the second fluid channel, and afirst portion of the isolation cavity. The fourth plate may bepositioned below the third plate and include portions defining at leasta portion of the first purge channel, as well as at least a secondportion of the isolation cavity that is in fluid communication with thefirst portion of the isolation cavity defined by the third plate. Theisolation cavity may be configured to produce a thermal barrier betweenthe first region of the pedestal and the second region of the pedestal.The assemblies may still further include a second purge channel definedalong an interface between the stem and the pedestal, and that isconfigured to provide a second purge flow path that is configured toproduce a thermal barrier between the stem and the pedestal. The secondpurge channel may at least partially be defined by an additional purgedistribution plate.

Substrate support assemblies are also described including a pedestalhaving a substrate support surface. The assemblies may additionallyinclude a stem coupled with the pedestal opposite the substrate supportsurface that includes a pair of stem internal channels configured todeliver and receive a temperature controlled fluid to the pedestal. Theassemblies may include a fluid channel defined within a central regionof the pedestal coupled at an inlet section with one of the pair of steminternal channels, and be configured to receive the temperaturecontrolled fluid from the stem internal channel. The fluid channel mayfurther be coupled at an outlet section with the other of the pair ofstem internal channels, and be configured to direct the temperaturecontrolled fluid to the other stem internal channel. The fluid channelmay include a first channel portion and a second channel portion betweenthe inlet and the outlet sections, and the second channel portion may bedisposed vertically from and coupled in parallel-reverse pattern withthe first channel portion. The channel portions may be configured suchthat fluid received at the inlet section is directed through the firstchannel portion prior to flowing through the second channel portion andthrough the outlet section. The fluid channel may also be arranged in acoil pattern that is configured to direct the temperature controlledfluid from the inlet section radially outward through the pedestal. Thestem of the assembly may further include a heating means separate fromthe stem internal channels, and be operable to maintain the stem at atemperature different from the pedestal. The first and second portionsof the fluid channel may be disposed vertically from one another indisclosed embodiments, and the portions may be in direct verticalalignment. The pedestal may further include a purge channel having adistally located outwardly closed cavity defined within the pedestal atleast partially below the fluid channel. The cavity may be located at aposition radially outward from the pedestal defining a region of thepedestal. The purge channel may be configured to receive a pressurizedfluid from a stem purge channel that is contained within the purgechannel to create a fluid barrier within the pedestal throughout thepurge channel. Additionally, the pedestal portion of the assemblies maybe formed from a plurality of plates coupled with one another to formthe pedestal.

Such technology may provide numerous benefits over conventionalequipment. For example, temperatures across the pedestal surface may bemaintained at more uniform temperatures, which may allow for improvedprocesses across the surface of a substrate being processed.Additionally, providing an assembly capable of having different regionsmaintained at different temperatures may allow more precise operationsto be performed, and may reduce the amount of material disposed onequipment surfaces. These and other embodiments, along with many oftheir advantages and features, are described in more detail inconjunction with the below description and attached figures.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the disclosedembodiments may be realized by reference to the remaining portions ofthe specification and the drawings.

FIG. 1 is a top plan view of one embodiment of a processing tool.

FIG. 2 is a schematic cross-sectional view of one embodiment of aprocessing chamber in which a pedestal according to the disclosedtechnology may be found.

FIG. 3 illustrates a cross-sectional view of a substrate supportassembly according to embodiments of the present technology.

FIG. 4 shows a partial cross-sectional view of a substrate supportassembly according to embodiments of the present technology.

FIG. 5 illustrates a top plan view of a component plate of a pedestalaccording to embodiments of the present technology.

FIG. 6 shows an exploded perspective view of component plates of apedestal according to embodiments of the present technology.

FIG. 7 illustrates a top perspective view of a component plate of apedestal according to embodiments of the present technology.

In the appended figures, similar components and/or features may have thesame numerical reference label. Further, various components of the sametype may be distinguished by following the reference label by a letterthat distinguishes among the similar components and/or features. If onlythe first numerical reference label is used in the specification, thedescription is applicable to any one of the similar components and/orfeatures having the same first numerical reference label irrespective ofthe letter suffix.

DETAILED DESCRIPTION

The present technology includes improved pedestal designs for heatingand cooling distribution during semiconductor processing operations.While conventional pedestals may control the general temperature of thesubstrate during operations, the presently described technology allowsfor improved control of the temperature characteristics across theentirety of the surface and exterior of the pedestal and stem. Thetechnology allows for the pedestal to be controlled in multipleindependent zones. In so doing, improved operations may be performedbecause a substrate residing on the pedestal can be maintained at a moreuniform temperature profile across the entire surface. These and otherbenefits will be explained in detail below.

FIG. 1 is a top plan view of one embodiment of a processing tool 100used in exemplary semiconductor manufacturing processes, and in which apedestal according to the present technology may be found. In thefigure, a pair of FOUPs (front opening unified pods) 102 supplysubstrates of a variety of dimensions that may be received by roboticarms 104 and placed into a low pressure holding area 106 before beingplaced into one of the substrate processing sections 108 a-f of thetandem process chambers 109 a-c. A second robotic arm 110 may be used totransport the substrates from the holding area 106 to the processingchambers 108 a-f and back.

The substrate processing sections 108 a-f of the tandem process chambers109 a-c may include one or more system components for depositing,annealing, curing and/or etching films on a substrate. In oneconfiguration, two pairs of the tandem processing sections of theprocessing chamber (e.g., 108 c-d and 108 e-f) may be used to deposit aflowable dielectric material on the substrate, and the third pair oftandem processing sections (e.g., 108 a-b) may be used to anneal thedeposited dielectric. In another configuration, the two pairs of thetandem processing sections of processing chambers (e.g., 108 c-d and 108e-f) may be configured to both deposit and anneal a flowable dielectricfilm on the substrate, while the third pair of tandem processingsections (e.g., 108 a-b) may be used for UV or E-beam curing of thedeposited film. In still another configuration, all three pairs oftandem processing sections (e.g., 108 a-f) may be configured to etchdielectric films deposited on the substrate.

In yet another configuration, two pairs of tandem processing sections(e.g., 108 c-d and 108 e-f) may be used for both deposition and UV orE-beam curing of the dielectric, while a third pair of tandem processingsections (e.g. 108 a-b) may be used for annealing the dielectric film.It will be appreciated that additional configurations of deposition,annealing, and curing chambers for flowable dielectric films arecontemplated by system 100.

In addition, one or more of the tandem processing sections 108 a-f maybe configured as a wet treatment chamber. These process chambers mayinclude heating the dielectric film in an atmosphere that includesmoisture. Thus, embodiments of system 100 may include wet treatmenttandem processing sections 108 a-b and anneal tandem processing sections108 c-d to perform both wet and dry anneals on the deposited dielectricfilm.

FIG. 2 shows a simplified cross-sectional view of a processing system200 according to embodiments of the present technology that may includepartitioned plasma generation regions within the processing chamber. Theprocessing system may optionally include components located outside theprocessing chamber 205, such as fluid supply system 210. The processingchamber 205 may hold an internal pressure different than the surroundingpressure. For example, the pressure inside the processing chamber may beabout 10 mTorr to about 20 Torr during processing.

During operation, a process gas may be flowed into the first plasmaregion 235 through a gas inlet assembly 240. The process gas may beexcited prior to entering the first plasma region 235 within a remoteplasma system (RPS) 215. A lid 220, a showerhead 225, and a substratesupport 245, having a substrate 255 disposed thereon, are shownaccording to disclosed embodiments. The lid 220 may be pyramidal,conical, or of another similar structure with a narrow top portionexpanding to a wide bottom portion, or may be relatively flat asdepicted. The lid 220 may include an applied AC voltage source and theshowerhead 225 may be grounded, consistent with plasma generation in thefirst plasma region 235. An insulating ring 230 may be positionedbetween the lid 220 and the showerhead 225 enabling a capacitivelycoupled plasma (CCP) to be formed in the first plasma region 235.

The lid 220 may be a dual-source lid for use with a processing chamberaccording to disclosed embodiments. A fluid inlet assembly 240 mayintroduce a fluid, such as a gas, into the first plasma region 235. Thefluid inlet assembly 240 may include two distinct fluid supply channelswithin the assembly. A first channel may carry a fluid, such as a gas,that passes through the RPS 215, while a second channel may carry afluid, such as a gas, that bypasses the RPS 215. The first channel maybe used for the process gas and the second channel may be used for atreatment gas in disclosed embodiments. The gases may flow into theplasma region 235 and be dispersed by a baffle (not shown). The lid 220and showerhead 225 are shown with an insulating ring 230 in between,which allows an AC potential to be applied to the lid 220 relative tothe showerhead 225.

A fluid, such as a precursor, may be flowed into the second plasmaregion 250 by embodiments of the showerhead 225 described herein.Excited species derived from the process gas in the plasma region 235may travel through apertures in the showerhead 225 and react with theprecursor flowing into the second plasma region 250 from the showerhead.Little or no plasma may be present in the second plasma region 250.Excited derivatives of the process gas and the precursor may combine inthe region above the substrate.

Exciting the process gas in the first plasma region 235 directly,exciting the process gas in the RPS 215, or both, may provide severalbenefits. The concentration of the excited species derived from theprocess gas may be increased within the second plasma region 250 due tothe plasma in the first plasma region 235. This increase may result fromthe location of the plasma in the first plasma region 235. The secondplasma region 250 may be located closer to the first plasma region 235than the RPS 215, leaving less time for the excited species to leaveexcited states through collisions with other gas molecules, walls of thechamber, and surfaces of the showerhead.

The uniformity of the concentration of the excited species derived fromthe process gas may also be increased within the second plasma region250. This may result from the shape of the first plasma region 235,which may be more similar to the shape of the second plasma region 250.Excited species created in the RPS 215 may travel greater distances inorder to pass through apertures near the edges of the showerhead 225relative to species that pass through apertures near the center of theshowerhead 225. The greater distance may result in a reduced excitationof the excited species and, for example, may result in a slower growthrate near the edge of a substrate. Exciting the process gas in the firstplasma region 235 may mitigate this variation.

The processing gas may be excited in the RPS 215 and may be passedthrough the showerhead 225 to the second plasma region 250 in theexcited state. Alternatively, power may be applied to the firstprocessing region to either excite a plasma gas or enhance an alreadyexited process gas from the RPS 215. While a plasma may be generated inthe second plasma region 250, a plasma may alternatively not begenerated in the second plasma region. In one example, the onlyexcitation of the processing gas or precursors may be from exciting theprocessing gas in the RPS 215 to react with the precursors in the secondplasma region 250.

The plasma generating gases and/or plasma excited species may passthrough a plurality of holes (not shown) in lid 220 for a more uniformdelivery into the plasma excitation region 235. Exemplary configurationsinclude having the inlet 240 open into a gas supply region 260partitioned from the plasma excitation region 235 by lid 220 so that thegases/species flow through the holes in the lid 220 into the plasmaexcitation region 235. Structural and operational features may beselected to prevent significant backflow of plasma from the plasmaexcitation region 235 back into the supply region 260, inlet 240, andfluid supply system 210. The structural features may include theselection of dimensions and cross-sectional geometry of the holes in lid220 that deactivates back-streaming plasma. The operational features mayinclude maintaining a pressure difference between the gas supply region260 and plasma excitation region 235 that maintains a unidirectionalflow of plasma through the showerhead 225.

The showerhead 225 may include a plurality of holes that suppress themigration of ionically-charged species out of the plasma excitationregion 235 while allowing uncharged neutral or radical species to passthrough the showerhead 225. These uncharged species may include highlyreactive species that are transported with less reactive carrier gasthrough the holes. As noted above, the migration of ionic speciesthrough the holes may be reduced, and in some instances completelysuppressed. Controlling the amount of ionic species passing through theshowerhead 225 may provide increased control over the gas mixturebrought into contact with the underlying wafer substrate, which in turnincreases control of the deposition and/or etch characteristics of thegas mixture.

The plurality of holes in the showerhead 225 may be configured tocontrol the passage of the activated gas (i.e., the ionic, radical,and/or neutral species) through the showerhead 225. For example, theaspect ratio of the holes (i.e., the hole diameter to length) and/or thegeometry of the holes may be controlled so that the flow ofionically-charged species in the activated gas passing through theshowerhead 225 is reduced. In embodiments where the showerhead 225includes an electrically coupled ion suppressor with the showerhead, theholes in the ion blocker, which may be disposed above the showerhead,may include a tapered portion that faces the plasma excitation region235, and a cylindrical portion that faces the showerhead. Thecylindrical portion may be shaped and dimensioned to control the flow ofionic species passing to the showerhead. An adjustable electrical biasmay also be applied to the showerhead 225 as an additional means tocontrol the flow of ionic species.

Depending on whether a deposition or an etching process is performed,gases and plasma excited species may pass through the showerhead 225 andbe directed to the substrate. The showerhead can further direct the flowof gases or plasma species. The showerhead may be a dual-zone showerheadthat may include multiple fluid channels for directing the flow of oneor more gases. The dual-zone showerhead may have a first set of channelsto permit the passage of plasma excited species into reaction region250, and a second set of channels that deliver a second gas/precursormixture into the reaction region 250.

A fluid delivery source may be coupled with the showerhead to deliver aprecursor that is able to bypass plasma excitation region 235 and enterreaction region 260 from within the showerhead through the second set ofchannels. The second set of channels in the showerhead may be fluidlycoupled with a source gas/precursor mixture (not shown) that is selectedfor the process to be performed. For example, when the processing systemis configured to perform an etch on the substrate surface, the sourcegas/precursor mixture may include etchants such as oxidants, halogens,water vapor and/or carrier gases that mix in the reaction region 250with plasma excited species distributed from the first set of channelsin the showerhead. Excessive ions in the plasma excited species may bereduced as the species move through the holes in the showerhead 225, andreduced further as the species move through channels in the showerhead.

The pedestal 245 may be operable to support and move the substrate orwafer 255. The distance between the pedestal 245 and the bottom of theshowerhead 225 help define the reaction region 250. The pedestal 245 maybe vertically or axially adjustable within the processing chamber 205 toincrease or decrease the reaction region 250 and affect the depositionor etching of the wafer substrate by repositioning the wafer substratewith respect to the gases passed through the showerhead 225.

The pedestal 245 may also be configured with a heating element such as aresistive heating element to maintain the substrate at heatingtemperatures (e.g., about 90° C. to about 1100° C.). Exemplary heatingelements may include a single-loop heater element embedded in thesubstrate support platter that makes two or more full turns in the formof parallel concentric circles. An outer portion of the heater elementmay run adjacent to a perimeter of the support platten, while an innerportion may run on the path of a concentric circle having a smallerradius. The wiring to the heater element may pass through the stem ofthe pedestal.

A dual-zone showerhead, as well as the processing system and chamber,are more fully described in patent application Ser. No. 13/251,714 filedon Oct. 3, 2011, which is hereby incorporated by reference for allpurposes to the extent not inconsistent with the claimed features anddescription herein.

Turning to FIG. 3, a cross-sectional view of a substrate supportassembly 300 according to embodiments of the present technology isillustrated. The support assembly 300 includes a pedestal 305 and stem310. The stem 310 may also include a base 312 upon which the pedestal305 is located. The pedestal 305 may include a substrate support surface315 that is configured to support a substrate during a semiconductorprocessing operation. The substrate support surface 315 may be made froma metal, such as aluminum, or a ceramic or other material, and may betreated or coated with other materials that provide improved corrosionresistance, improved contact with the substrate, etc.

The stem 310 may be attached to the pedestal 305 opposite the substratesupport surface 315. The stem 310 may include one or more internalchannels 320 configured to deliver and receive temperature controlledfluids, pressurized fluids, or gases to and from the pedestal 305. Anexemplary stem 310 may include four internal channels 320 that may bedivided into pairs. Alternative arrangements may include more or lesschannels, and may include 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, etc., or morechannels for fluid delivery. A first pair of internal channels 320 maybe configured to deliver and receive, respectively through the channels,a first temperature controlled fluid to the pedestal 305. A second pairof internal channels 320 may be configured to deliver and receive,respectively through the channels, a second temperature controlled fluidto the pedestal 305. The stem may also include one or more heating meansoperable to maintain a temperature of the stem different from thetemperatures maintained in the pedestal. For example, the stem mayinclude a fluid circulation system jacketed around, or integratedwithin, the stem. Alternatively, the stem 310 may also be configuredwith a heating element such as a resistive heating element to maintainthe stem at a particular temperature (e.g., about 90° C. to about 1100°C.). The wiring to the heater element may pass through the stem of thepedestal or be otherwise directed through the chamber. By maintainingthe stem at a suitable temperature, it may be possible to limit orprevent deposition on the stem portion of the support assembly 300.

The first and second temperature controlled fluids may be delivered tothe same or different regions of the pedestal through fluid channelslocated in the pedestal 305. For example, the first temperaturecontrolled fluid may be delivered to a first fluid channel 325 within afirst region 330 of the pedestal 305. The second temperature controlledfluid may be delivered to a second fluid channel 335 within a secondregion 340 of the pedestal 305. The two fluids may be the same ordifferent fluids, and may be provided at the same or differenttemperatures in order to maintain the two regions 330, 340 at similar ordifferent temperatures. For example, the second temperature controlledfluid may be delivered at a temperature greater than or less than thefirst temperature controlled fluid, which will allow the second region340 to be at a higher or lower, respectively, temperature than the firstregion 330. This can be used to affect etching and deposition profilesacross a wafer, and can also be used to affect how much deposition oretching occurs at different locations. Circulation of the temperaturecontrolled fluids allows the substrate temperature to be maintained atrelatively low temperatures, e.g., about −20° C. to about 150° C., aswell as at much higher temperatures, e.g., about 90° C. to about 1100°C. The temperatures may alternatively be maintained at between about 0°C. and 100° C., less than or about 100° C., etc. Exemplary heat exchangefluids include ethylene glycol and water, but other fluids may beutilized. In alternative assemblies 300, a resistive heating element isdisposed within the channels to provide heating energy for heating asubstrate. In still another alternative, the fluid channels areconfigured to include both a resistive heating element as well as spacefor circulation of a temperature controlled fluid such that multipleoptions of temperature control may be afforded.

Each of the first and second fluid channels may be coupled with the steminternal channels 320 at both an inlet and an outlet for receiving anddelivering the temperature controlled fluids. The temperature controlledfluids may then be circulated through the fluid channels to provide asubstantially uniform temperature control in the pedestal regions. Insome embodiments, the first and second fluid channels are fluidlyisolated from one another. The fluid channels may be arranged in avariety of patterns including spiral, coil, or other geometric patternsthat will circulate the temperature controlled fluids through thepedestal regions.

The fluid channel circulation may be similar between the first andsecond region, and will be explained herein with regard to the firstregion 330. The first fluid channel 325 may be coupled with one of afirst pair of stem internal channels 320 at a first inlet 327 to receivethe first temperature controlled fluid. The first fluid channel 325 maybe coupled with the other of the first pair of stem internal channels320 at a first outlet 329 to deliver the first temperature controlledfluid after it has been circulated through the first region 330 of thepedestal 305. The first fluid channel 325 may include a first portion331 and a second portion 333 between the inlet 327 and outlet 329. Thesecond portion 333 may be disposed vertically from the first portion331, and in alternative embodiments may be located above or below thefirst portion 331. In alternative arrangements, the second portion 333may be disposed horizontally from the first portion 331. The first andsecond portions may also be disposed in an exact vertical arrangementwith each other, with the first portion 331 disposed directly above thesecond portion 333, for example. Alternatively, the second portion 333may be displaced from a directly vertical relationship to either side.

The arrangement of the first and second portions of the first fluidchannel may be such as to create one of a variety of flow patterns forthe first temperature controlled fluid. In one embodiment, the first andsecond portion are arranged to produce a parallel-reverse flow patternfor the first temperature controlled fluid. Specifically, thetemperature controlled fluid, after being received at the first inlet327, may flow through the first portion of first fluid channel from alocation proximate to the stem internal channels outwardly to a distalportion of the first region 330. The temperature controlled fluid maythen be transferred between the first and second portions of the firstfluid channel and flow from a distal portion of the first region 330inwardly to a location proximate to the stem internal channels. Thetemperature controlled fluid may then be delivered to the stem internalchannels 320 at the first outlet 329.

Providing a parallel-reverse flow arrangement where the two channels arein close proximity may provide improved temperature control by producinga more uniform temperature profile across the substrate support surface.For example, when the channels are in direct vertical alignment asshown, general areas of fluid flow may average to a uniform temperature.As fluid is flowed through the channels, heat may be dissipated orabsorbed, depending on the temperature of the fluid. As the temperatureof the fluid changes, the temperature of the pedestal may not remainuniform at all locations. However, when a parallel-reverse flowarrangement of vertically aligned channels is provided, fluidtemperature averaging may occur. For example, when the fluid is used forcooling, the point of entry may have the lowest fluid temperature, andthe point of exit may have the highest fluid temperature. Accordingly,because these portions of the channel may be in close proximity, thefluid may provide a particular temperature within that region. At adistal portion of the region, the fluid may be at a temperature betweenthe fluid temperatures at the inlet and outlet, and as the fluidreverses flow at the distal area, the particular temperature within thatregion may be similar to the averaged temperature near the stem.Accordingly, a more uniform temperature profile across the pedestal maybe provided based on the fluid rate of flow and the channel orientation,which may not be available in conventional designs.

Although several of the components of the second fluid channel 335,including the inlet and outlet, are not shown in FIG. 3 for the sake ofclarity, the second fluid channel 335 may be arranged in the secondregion 340 in a similar fashion. For example, the second fluid channel335 may be configured to provide substantially uniform temperaturecontrol within the second region 340 of the pedestal 305. The secondfluid channel 335 may be coupled with a second inlet to receive thesecond temperature controlled fluid from one of a second pair of steminternal channels 320, and coupled with a second outlet to deliver thesecond temperature controlled fluid to the other of the second pair ofstem internal channels 320. The second fluid channel may include a thirdportion 337, and a fourth portion 339, where the third portion 337 isdisposed vertically from and arranged in a parallel-reverse pattern withthe fourth position 339. In this way, the fluid received at the secondinlet may be circulated through the third portion 337 prior to flowingthrough the fourth portion 339, and then through the second outlet. Thecirculation of fluid, and the arrangement of the channel, may be similarto that of the first fluid channel, or may be one of the alternativearrangements discussed above. As with the first fluid channel, the thirdand fourth portions of the second fluid channel may be disposedvertically from one another, or in an alternative configuration. Thethird and fourth portions may also be disposed in an exact verticalarrangement with each other, with the third portion 337 disposeddirectly above the fourth portion 339, for example. Alternatively, thefourth portion 339 may be displaced from a directly verticalrelationship to either side. In yet another alternative, the fourthportion 339 may be disposed above the third portion 337 of the secondfluid channel 335, or the direction of flow may be reversed. AlthoughFIG. 3 shows a single loop for the second fluid channel, any number ofloops may be provided based on the channel orientation and dimensions aswell as the pedestal dimensions. As with the first fluid channel, thesecond fluid channel may include any number of connected or spiraledrings around the region, and may in different embodiments include one ormore rings and up to or greater than 3, 4, 5, 6, 7, 8, 9, 10, etc. ormore loops of the channel.

The substrate support surface 315 may be of a variety of shapesincluding circular, elliptical, or other geometric shapes. One exemplarypedestal of the technology is substantially circular, with the firstregion 330 centrally located on the pedestal, and the second region 340being of an annular shape and surrounding the first region. Each regionmay also be of a similar or different outer shape than the other.Additional regions may similarly be developed as portions of a regionwith separate fluid channels, or additional annular sections disposedradially outward from one another.

The pedestal 305 and stem 310 may be isolated from one another on theassembly 300. For example, at contact points 345 and 350, additionalmaterial may be disposed that allows the pedestal 305 and stem 310 to beelectrically and/or thermally isolated from one another. At a firstcontact position 345, an o-ring, ceramic ring, or other insulativematerial may be positioned between the pedestal 305 and stem 310 so thatthe two portions of the assembly 300 are not in direct, or are inlimited, physical contact. Similarly, at contact position 350 an o-ring,ceramic ring, or other insulative material may be positioned between thepedestal 305 and stem 310. One benefit to this arrangement, is that thestem may be maintained at a temperature that is significantly higher,for example, than the pedestal such that the substrate may be kept at arelatively low temperature during a deposition operation, but the stemmay be kept at a higher temperature that limits deposition on thesurface of the assembly 300. By providing thermal isolation between thesections, the temperature of the stem may not impact or may minimallyimpact the temperature of the substrate at any location. Additionally,the material utilized at contact position 350 may be a material that iselectrically insulative, but may provide conductive heat transfer suchthat the edge of pedestal 305 may be heated similar to the stem 310, butis electrically isolated from the stem.

The substrate support surface 315 may be one component plate of thepedestal assembly 320, which may include a plurality of plates bonded,welded, fused, or otherwise coupled with each other. In an exemplaryembodiment, the pedestal assembly 320 includes five plates, and inalternative embodiments, the pedestal assembly includes less than fiveplates, more than five plates, at least three plates, etc. The substratesupport surface 315 may be the first plate of the assembly. The pedestalassembly 320 may include a second plate which at least partially definesthe fluid channels. The plate arrangement and configuration is describedfurther below.

FIG. 4 shows a partial cross-sectional view of a substrate supportassembly 400 according to embodiments of the present technology. Theassembly 400 may include similar components as described above withregard to FIG. 3. As shown, assembly 400 includes pedestal 405 and stem410. The pedestal may include a substrate support surface 415 aspreviously discussed. The pedestal 405 may include multiple regions,which may include, for example, a first region 430 and a second region440. Each region may include fluid channels that circulate a temperaturecontrolled fluid configured to heat or cool the pedestal 405 to apredetermined temperature. The channels may alternatively, oradditionally, include heating elements that may allow for resistiveheating to be provided through the channels for further adjustment ofthe pedestal 405 temperature. The first region 430 may include a firstchannel 425, and the second region 440 may include a second channel 435.As discussed previously, the first and second channels may be fluidlyisolated such that a different temperature controlled fluid may becirculated through each of the first and second regions. In one example,the second region may be maintained at about 100° C., while the firstregion may be maintained at about 50° C., or vice versa. Any particulartemperature in the ranges previously described can be maintainedseparately in either of the first or second regions. In this way,multiple temperature arrangements may be utilized with each region beingmaintained at the same or a different temperature than the other region.

The pedestal 405 may also include one or more purge channels definedwithin the pedestal, and configured to provide purge flow paths. Forexample, a first purge flow path 450 may be defined by a portion of thepedestal 405. An exemplary pedestal 405 may include a plurality ofbonded plates, which may include a plate defining the first purge flowpath 450. The first purge flow path 450 may circulate a purge fluidthroughout the pedestal that is evacuated through a plurality of purgeoutlets 455 defined in the pedestal 405. Although FIG. 4 illustrates onepurge outlet 455, any number of purge outlets may be included indifferent configurations, and may be included in one or more rings ofoutlets within the pedestal. This feature will be discussed in moredetail with reference to FIG. 5 below.

The first purge path 450 may be configured in any number of patternswithin the pedestal 405. For example, the first purge path 450 may beconfigured in a coil pattern throughout the pedestal 405 in order toprovide thermal isolation between the substrate support surface 415 andthe stem 410 that may be heated as described above. Alternatively, aplurality of straight channels may be formed in the pedestal that directa purge fluid directly to the purge outlets 455. Many differentvariations may be provided with the first purge channel 450, and may bearranged to provide a uniform purge flow across the pedestal. A purgefluid may be delivered from internal channels 420 in the stem 410,through the first purge channel 450, and out through purge outlets 455.The purge fluid may be a gas, including an inert gas, which is utilizedto limit or prevent the formation of process byproducts within holes orchannels of the substrate support surface 405. When deposition and/oretch processes are performed, byproducts of the process will routinelycondense on areas within the substrate processing chamber, including onthe substrate support assembly. When these byproducts accumulate on andwithin the substrate support surface 415, a subsequent substratepositioned on the surface may tilt, which can result in non-uniformdeposition or etching. A purge gas delivered through the pedestal may becapable of dislodging and removing reactants from the substrate supportsurface.

The first purge channel 450 may additionally include a verticalisolation cavity 460 at a distal portion of the first purge channel 450.The vertical isolation cavity may be located at the periphery of thefirst region 430, and may be configured to receive a portion of thepurge gas flow through the first purge channel 450, where the portion ofpurge gas is maintained in the isolation cavity 460 to provide thermalisolation between the first region 430 and the second region 440. Insome arrangements, multiple purge channels are included to separatelydeliver gas to the isolation cavity 460 and the purge outlets 455. Thechannel or channels coupled with the isolation cavity 460 may beoutwardly closed, such that the channel may be pressurized with fluid. Apressurized gas or pressurized fluid may be delivered to the isolationcavity, or pressurized within the cavity to provide a barrier ortemperature curtain at the location of the isolation cavity. Theisolation cavity 460 may be arranged as a channel that may separate thefirst and second regions 430, 440 around the entire pedestal. The purgegas or fluid may be heated or cooled to be delivered to the isolationcavity 460 such that it does not affect the temperature control of thetemperature controlled fluids being circulated in the pedestal regions.Alternatively, the purge gas may be delivered at a temperature selectedto adjust the temperature profile across the pedestal. In an exemplarypedestal, the isolation cavity 460 may be distributed across multipleplates of the pedestal. For example, the substrate support surface maybe a first plate in the pedestal, and the first and second fluidchannels 425, 435 may be at least partially defined in the second plateof the pedestal. The second plate may also at least partially define afirst portion of the isolation cavity 460. The third plate may at leastpartially define the first purge channel 450 as well as a second portionof the isolation cavity 460 that is in fluid communication with thefirst portion of the isolation cavity defined by the second plate. Inthis way, the isolation cavity 460 may be utilized by delivering aportion of the purge gas to the cavity that may create a thermal barrierbetween the first and second fluid channels 425, 435, and between thefirst region 430 and the second region 440 of the pedestal 405.

The pedestal 405 may also include a second purge channel 465 that may bedefined along an interface between the stem 410 and the pedestal 405.The second purge channel 465 may be configured to provide a second purgeflow path for a purge gas that may produce an additional thermal barrierbetween the stem 410 and the pedestal 405. Accordingly, in one example,heat applied to the stem 410 to limit the amount of deposition ofprocess byproducts may not affect the temperature control scheme appliedthrough the pedestal 405. The second purge channel 465 may additionallyinclude a second isolation cavity and purge outlet 470. The secondisolation cavity and purge outlet 470 may be configured to receive aportion of purge gas delivered through the second purge channel 465, andmay provide additional thermal isolation between the edge of thepedestal 475, and the second region 440 of the pedestal 405.Accordingly, the edge of the pedestal 475 may be heated in a fashionsimilar to the stem 410 in order to reduce the amount of byproductdeposition on the equipment, while providing a barrier to the pedestal405 such that a uniform temperature profile may be more readily providedon the substrate support surface 415 in the second region 440.

The second isolation cavity 470 may function and be arranged in asimilar fashion as the first isolation cavity 460. Purge gas or fluidmay be delivered from internal channels 420 in the stem 410, and may bethe same or different internal channels 420 as those delivering purgegas to the first purge channel 450. The purge gas delivered to the firstand second purge channels 450, 465 may be the same or different inalternative embodiments. The purge gas may be delivered through thesecond purge channel 465 and into the second isolation cavity 470, priorto being expelled through the purge outlet at the top of the isolationcavity 470. The purge outlet at the top of isolation cavity 470 may besimilar to the outlets 455 through which the first purge gas isdelivered. Alternatively, a space may be created around the entirety ofthe top of the second isolation cavity 470 for the flow of purge gas.Alternatively, second isolation cavity 470 may be outwardly closed suchthat fluid buildup or pressurization may be performed in the secondisolation cavity providing an enhanced thermal barrier at the externaledge of the pedestal.

FIG. 5 illustrates a top plan view of a component plate 500 of apedestal according to embodiments of the present technology. Plate 500may be one of several component plates forming the pedestal. Plate 500includes a first fluid channel 525 disposed within a first region 530,as well as a second fluid channel 535 disposed within a second region540. The first fluid channel is arranged in a coil pattern, but canalternatively be arranged in a spiral, or other geometric pattern forcirculation of a temperature controlled fluid. FIG. 5 illustrates afirst portion of the channels, i.e., a top portion, but the plate mayadditionally define a second portion of the channels underneath. The topand bottom portions may be mirror images of one another, or may be areverse pattern. In one exemplary plate 500, a temperature controlledfluid is delivered through the center of the plate to the first fluidchannel 525 and delivered outwardly toward a distal position in thefirst fluid channel 525. The temperature controlled fluid may then betransferred to the bottom portion of the fluid channel (not shown) whereit is circulated in a parallel-reverse pattern in comparison to the topportion of the fluid channel 525 back toward the center of the plate.The receiving and delivering of the temperature controlled fluid to thefirst fluid channel may occur through connections with internal channelsof the stem of the support assembly.

Plate 500 also includes second fluid channel 535 arranged in a coilaround the second region 540 of the plate 500, for circulation of atemperature controlled fluid that may be the same or different than thetemperature controlled fluid delivered through the first fluid channel525. Although shown in a single pass arrangement multiple passes or coilconfigurations may be utilized depending on the size of the plate 500.Second fluid channel 535 may also include a second portion on theunderside of the plate (not shown), to provide a parallel-reversecirculation arrangement of a second temperature controlled fluid.

Plate 500 also may include an isolation cavity 560 that can be utilizedto produce a thermal barrier between the first region 530 and the secondregion 540 of the plate 500. The isolation cavity may be configured toreceive a purge fluid that may fill the isolation cavity 560. The cavity560 may be arranged in a single channel, or in multiple channels asshown in FIG. 5. When assemblies including multiple regions areutilized, the pattern of the fluid channel may affect the ability toinclude multiple regions. For example, by providing a coiled patternsuch as shown in FIG. 5 for first fluid channel 525, an area is providedbetween the coils allowing access to be provided to the second fluidchannel 535. A spiral channel, for example, may also be utilized for thefirst fluid channel 525, but such a configuration may block access tothe second fluid channel, where the two channels may otherwiseintersect. If identical fluids are being provided, this intersection maybe provided in the channel scheme, but if different fluids or fluids ofdifferent temperature are being utilized, such an intersectingarrangement may not be practical.

Plate 500 may still further include purge outlets 555 that may beutilized to remove, limit, or prevent process byproducts from beingdeposited on the pedestal substrate support surface. The purge outlets555 may be configured in one or more rings, or alternatively disposed invarious positions across the plate 500. As illustrated in FIG. 5, as oneexample, the outlets are positioned in two rings, but any number ofrings may be used including 0, 1, 2, 3, 4, 5, 6, 7, 8, etc., or morerings. As illustrated in the embodiment shown in FIG. 5, an inner ringincludes purge outlets 555 a, and an outer ring includes purge outlets555 b. Any number of outlets may be arranged on the plate 500. Asillustrated, the inner ring may include about 12 or less purge outlets555 a. Alternatively, the inner ring may include less than or about 10,8, 6, 4, or 2 outlets 555 a, and in some embodiments, an inner ring ofpurge outlets 555 a may not be included. Additionally, the outer ringmay include more than, about 48, or less purge outlets 555 b.Alternatively, the outer ring may include less than or about 40, 32, 24,20, 16, 12, 8, 4, or 2 purge outlets 555 b. Again, in some plateconfigurations, an outer ring of purge outlets 555 b may not beincluded. Additional rings may also be utilized that include the same ora different number of purge outlets 555 as the inner and outer ringdescribed.

FIG. 6 shows an exploded perspective view of component plates of apedestal according to embodiments of the present technology. Asillustrated in the figure, five component plates are used, but more orless plates may be utilized in different embodiments of the technology.First plate 610 may comprise the substrate support surface on which asubstrate may be positioned for processing. The plate may include atleast a portion of purge gas outlets 618. Below first plate 610 may be asecond plate 620. The second plate 620 may include areas defining atleast part of the first and second portions of the first fluid channel622, at least part of the third and fourth portions of the second fluidchannel 624, and at least a first portion of the first purge channel626. The second plate 620 may additionally include portions of the purgeoutlets 628 distributed across the plate.

Below second plate 620 may be a third plate 630. Third plate 630 mayinclude areas defining at least a second portion of the first purgechannel 636. The portion of the first purge channel 636 may beconfigured to be in fluid communication with the first portion of thefirst purge channel 626 defined by the second plate 620. The third platemay also include portions of the purge outlets 638 distributed acrossthe plate. Below the third plate 630 may be a fourth plate 640. Thefourth plate may provide additional insulation between the substratesupport surface and the stem, and may additionally at least partlydefine the first purge channel that may be at least partly disposed onthe backside of the third plate 630. Finally, a fifth plate 650 may belocated below the fourth plate. The fifth plate may provide stilladditional thermal isolation between the substrate support surface andthe stem, and in some embodiments, the fifth plate may include areasdefining at least part of the third and fourth portions of the secondfluid channel 655. The second temperature controlled fluid may bedelivered from the stem internal channels, as described previously, andmay be circulated across the fifth plate to connections (not shown) thatdeliver the temperature controlled fluid up to the second plate 620 forcirculation through the second region of the pedestal. Each of theplates 620, 630, 640, and 650 may include additional connections throughwhich the first temperature controlled fluid may be delivered to thefirst fluid channel 622 in second plate 620.

FIG. 7 illustrates a top perspective view of a component plate of apedestal 700 according to embodiments of the present technology. Asillustrated, pedestal 700 may further include a purge distribution plate710 that at least partially defines the second purge channel describedpreviously. The distribution plate 710 may be made of a ceramic, orother material that may have a low thermal conductivity. The secondpurge channel may provide thermal isolation between the pedestal andstem, to improve the uniformity of the temperature profile across asubstrate. When included below pedestal component plates, as illustratedin one example in FIG. 6, the second purge channel may be fully defined.A plurality of orifices may be utilized to further define the flow pathof a purge gas within the second purge channel.

For example, purge gas may be delivered up through the stem throughinternal channels 705. The purge gas may then proceed under the fifthplate of the exemplary design of FIG. 6, or a bottom plate, to initialorifices 712 of purge distribution plate 710. The purge gas may flowthrough the orifices 712 and under the purge distribution plate 710 toan area that may be at least partially defined by stem base 708. Thepurge gas may flow back up through orifices 714, down through orifices716, up through orifices 718, down through orifices 720, and then thepurge gas may be delivered to the second isolation cavity 725. The purgedistribution plate may include a greater or a fewer number of orificepaths depending on the application. The purge distribution plate may bemade of a metal, ceramic, plastic, or other material that may facilitateflow of the purge gas, and/or minimize heat transfer between the stemand the pedestal.

In the preceding description, for the purposes of explanation, numerousdetails have been set forth in order to provide an understanding ofvarious embodiments of the present technology. It will be apparent toone skilled in the art, however, that certain embodiments may bepracticed without some of these details, or with additional details.

Having disclosed several embodiments, it will be recognized by those ofskill in the art that various modifications, alternative constructions,and equivalents may be used without departing from the spirit of thedisclosed embodiments. Additionally, a number of well-known processesand elements have not been described in order to avoid unnecessarilyobscuring the present technology. Accordingly, the above descriptionshould not be taken as limiting the scope of the technology.

Where a range of values is provided, it is understood that eachintervening value, to the smallest fraction of the unit of the lowerlimit, unless the context clearly dictates otherwise, between the upperand lower limits of that range is also specifically disclosed. Eachsmaller range between any stated value or intervening value in a statedrange and any other stated or intervening value in that stated range isencompassed. The upper and lower limits of those smaller ranges mayindependently be included or excluded in the range, and each range whereeither, neither, or both limits are included in the smaller ranges isalso encompassed within the invention, subject to any specificallyexcluded limit in the stated range. Where the stated range includes oneor both of the limits, ranges excluding either or both of those includedlimits are also included.

As used herein and in the appended claims, the singular forms “a”, “an”,and “the” include plural references unless the context clearly dictatesotherwise. Thus, for example, reference to “a dielectric material”includes a plurality of such materials, and reference to “theapplication” includes reference to one or more applications andequivalents thereof known to those skilled in the art, and so forth.

Also, the words “comprise”, “comprising”, “contains”, “containing”,“include”, “including”, and “includes”, when used in this specificationand in the following claims, are intended to specify the presence ofstated features, integers, components, or steps, but they do notpreclude the presence or addition of one or more other features,integers, components, steps, acts, or groups.

What is claimed is:
 1. A substrate support assembly comprising: apedestal having a substrate support surface; a stem coupled with thepedestal opposite the substrate support surface, the stem including apair of stem internal channels configured to deliver and receive atemperature controlled fluid to the pedestal; a fluid channel definedwithin a central region of the pedestal, the fluid channel coupled at aninlet section with, and configured to receive the temperature controlledfluid from, one of the pair of stem internal channels, coupled at anoutlet section with, and configured to direct the temperature controlledfluid to, the other of the pair of stem internal channels, and includinga first channel portion and a second channel portion between the inletand the outlet sections, wherein the second channel portion is disposedvertically from and coupled in a parallel-reverse pattern with the firstchannel portion, and wherein the first and second channel portions areconfigured such that fluid received at the inlet section is directedthrough the first channel portion prior to flowing through the secondchannel portion and through the outlet section.
 2. The substrate supportassembly of claim 1, wherein the fluid channel is arranged in a coilpattern configured to direct the temperature controlled fluid from theinlet section radially outward through the pedestal.
 3. The substratesupport assembly of claim 1, wherein the stem comprises a heating meansseparate from the stem internal channels, and operable to maintain thestem at a temperature different from the pedestal.
 4. The substratesupport assembly of claim 1, wherein the first and second portions ofthe fluid channel are disposed vertically from each other in directvertical alignment.
 5. The substrate support assembly of claim 1,further comprising a purge channel having a distally located outwardlyclosed cavity, wherein the purge channel is defined within the pedestalat least partially below the fluid channel, and configured to receive apressurized fluid from a stem purge channel that is contained within thepurge channel to create a fluid barrier within the pedestal throughoutthe purge channel.
 6. The substrate support assembly of claim 1, whereinthe pedestal comprises a plurality of plates coupled with one another toform the pedestal.
 7. A substrate support assembly comprising: apedestal having a substrate support surface; a stem coupled with thepedestal opposite the substrate support surface, the stem including apair of stem internal channels configured to deliver and receive atemperature controlled fluid to the pedestal; a fluid channel definedwithin a central region of the pedestal, the fluid channel including afirst channel portion and a second channel portion, wherein the secondchannel portion is disposed vertically from the first channel portion,and wherein the first and second channel portions are configured suchthat fluid is directed through the first channel portion prior toflowing through the second channel portion.
 8. The substrate supportassembly of claim 7, wherein the fluid channel is arranged in a coilpattern configured to direct the temperature controlled fluid radiallyoutward through the pedestal via the first channel portion.
 9. Thesubstrate support assembly of claim 7, wherein the stem comprises aheater separate from the stem internal channels, wherein the heater isoperable to maintain the stem at a temperature different from thepedestal.
 10. The substrate support assembly of claim 7, wherein thefirst and second channel portions of the fluid channel are disposedvertically from each other in direct vertical alignment.
 11. Thesubstrate support assembly of claim 7, further comprising a purgechannel having a distally located and outwardly closed cavity, whereinthe purge channel is defined within the pedestal at least partiallybelow the fluid channel, and configured to receive a pressurized fluidfrom a stem purge channel that is contained within the purge channel tocreate a fluid barrier within the pedestal throughout the purge channel.12. The substrate support assembly of claim 7, wherein the pedestalcomprises a plurality of plates coupled with one another to form thepedestal.